CN206164934U - Linear constant -current drive circuit of LED and LED lighting device - Google Patents

Linear constant -current drive circuit of LED and LED lighting device Download PDF

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Publication number
CN206164934U
CN206164934U CN201621279698.6U CN201621279698U CN206164934U CN 206164934 U CN206164934 U CN 206164934U CN 201621279698 U CN201621279698 U CN 201621279698U CN 206164934 U CN206164934 U CN 206164934U
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China
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constant
module
current
output
led
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李照华
林道明
胡乔
符传汇
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Shenzhen Mingwei Electronic Co Ltd
Shenzhen Sunmoon Microelectronics Co Ltd
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Shenzhen Mingwei Electronic Co Ltd
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02BCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
    • Y02B20/30Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

The utility model belongs to the LED drive control field provides a linear constant -current drive circuit of LED and LED lighting device, including rectifier module, cluster and conversion module, a constant current driver module, the 2nd constant current driver module, the 3rd constant current driver module and switch module, if rectifier module's output voltage is less than or equal to a presupposition voltage threshold value, a constant -current control module and the 2nd constant -current control module carry out the constant current control to parallel connection's LED lamp cluster and the 2nd LED lamp cluster respectively, if rise to on rectifier module's the output voltage and be greater than a presupposition voltage threshold value and continue to rise and be lighter than the 2nd presupposition voltage threshold value, a cluster and a conversion module control constant -current control module carry out constant power control to the input power of back level circuit, if rise to on rectifier module's the output voltage and be more than or equal to the 2nd presupposition voltage threshold value, the 3rd constant -current control module carries out the constant current control to two lamp clusters of series connection to wide input voltage's application has been realized.

Description

A kind of LED linear constant-current drive circuit and LED light device
Technical field
The utility model belongs to LED drive controls field, more particularly to a kind of LED linear constant-current drive circuit and LED shine Bright device.
Background technology
In recent years, LED (Light Emitting Diode, light emitting diode) lamp replaces traditional incandescent lamp, fluorescent lamp Deng being widely used as mains lighting supply.Common LED type of drive is divided into Switching Power Supply and drives and Linear Driving, its In, Linear Driving is widely popularized with its simple structure and cheap cost.
However, existing LED linear constant-current drive circuit cannot realize the application of wide input voltage, i.e. output loading LED The quantity of lamp determines that input voltage can only change in the range of a very little, if input voltage is less than operating voltage, LED Cannot light;If input voltage is higher than operating voltage, driving power consumption is increased, and temperature rises, and affects the reliability of LED.
In summary, the alterable scope of the input voltage of existing LED linear constant-current drive circuit is less, it is impossible to realize The application of wide input voltage.
Utility model content
The purpose of this utility model is to provide a kind of LED linear constant-current drive circuit and LED light device, it is intended to solved The alterable scope of the input voltage of existing LED linear constant-current drive circuit is less, it is impossible to realize the application of wide input voltage Problem.
The utility model is achieved in that a kind of LED linear constant-current drive circuit, with the first LED string and the 2nd LED Lamp series winding connects, and the LED linear constant-current drive circuit includes rectification module, and the rectification module carries out rectification to alternating current, and Output direct current is that the first LED string and the second LED string are powered, the LED linear constant-current drive circuit Also include serioparallel exchange module, the first constant-current driven module, the second constant-current driven module, the 3rd constant-current driven module and switching molding Block;
The first end of the serioparallel exchange module, the input of the 3rd constant-current control module and the second constant current control The input of molding block is connected to altogether the first output end of the rectification module, the output end of the 3rd constant-current control module and institute State the input connection of the first LED string, the second end of the serioparallel exchange module, the output of first constant-current driven module Second output end of end, the output end of the second LED string and the rectification module is connected to altogether ground, first current constant control The input of module is connected to altogether the input of the switch module, first constant current with the output end of the first LED string The voltage input end and controlled end of drive module is connected respectively with the output end and control end of the serioparallel exchange module, and described The controlled end and output end of two constant-current driven modules is defeated with the output end of the switch module and the second LED string respectively Enter end connection;
When the output voltage of the rectification module is less than or equal to the first predetermined voltage threshold, the switch module is closed Disconnected, the first LED string and the second LED connection in series-parallel connect, first constant-current control module and described second permanent Flow control module carries out current constant control to the first LED string and the second LED string respectively;When the rectification module Output voltage rises to more than the first predetermined voltage threshold and continues to rise and during less than the second predetermined voltage threshold, and the string is simultaneously Modular converter is adjusted to the output current of first constant-current control module, and then the input power to late-class circuit is carried out Power limitation control;When the output voltage of the rectification module is continued to rise to more than or equal to the second predetermined voltage threshold, institute State switch module conducting, the first current constant control mould and second constant-current control module are turned off, the first LED string and The second LED string is connected in series, and the 3rd constant-current control module is to the first LED string and second LED String carries out current constant control.
The utility model additionally provides a kind of LED linear constant-current drive circuit, with the first LED string and the second LED string Connection, the LED linear constant-current drive circuit includes rectification module, and the rectification module carries out rectification to alternating current, and exports Direct current is that the first LED string and the second LED string are powered, and the LED linear constant-current drive circuit is also wrapped Include serioparallel exchange module, the first constant-current driven module, the second constant-current driven module, the 3rd constant-current driven module and switch module;
The first end of the serioparallel exchange module, the input of the first LED string and the second current constant control mould The input of block is connected to altogether the first output end of the rectification module, the second end of the serioparallel exchange module, described first permanent Output end, the output end of the 3rd constant-current control module and the second output end of the rectification module for flowing drive module connects altogether Yu Di, the input of first constant-current control module is connected to altogether the switch module with the output end of the first LED string Input, the voltage input end and controlled end of first constant-current driven module respectively with the output of the serioparallel exchange module End and control end connection, the controlled end and output end of second constant-current driven module respectively with the output end of the switch module With the input connection of the second LED string, the output end of the second LED string and the 3rd constant-current control module Input connects;
When the output voltage of the rectification module is less than or equal to the first predetermined voltage threshold, the switch module is closed Disconnected, the first LED string and the second LED connection in series-parallel connect, first constant-current control module and described second permanent Flow control module carries out current constant control to the first LED string and the second LED string respectively;When the rectification module Output voltage rises to more than the first predetermined voltage threshold and continues to rise and during less than the second predetermined voltage threshold, and the string is simultaneously Modular converter is adjusted to the output current of first constant-current control module, and then the input power to late-class circuit is carried out Power limitation control;When the output voltage of the rectification module is continued to rise to more than or equal to the second predetermined voltage threshold, institute State switch module conducting, the first current constant control mould and second constant-current control module are turned off, the first LED string and The second LED string is connected in series, and the 3rd constant-current control module is to the first LED string and second LED String carries out current constant control.
The utility model additionally provides a kind of LED light device, is connected with AC power, and including the first LED string and Second LED string, the LED light device also includes above-mentioned LED linear constant-current drive circuit.
The LED linear constant-current drive circuit that the utility model is provided includes rectification module, serioparallel exchange module, the first constant current Drive module, the second constant-current driven module, the 3rd constant-current driven module and switch module;When the output voltage of rectification module is less than Or during equal to the first predetermined voltage threshold, switch module is turned off, the first LED string and the second LED connection in series-parallel connect, and first is permanent Flow control module and the second constant-current control module carry out current constant control to the first LED string and the second LED string respectively;Work as rectification The output voltage of module rises to more than the first predetermined voltage threshold and continues to rise and during less than the second predetermined voltage threshold, string And modular converter is adjusted to the output current of the first constant-current control module, and then the input power to late-class circuit carries out perseverance Power Control;When the output voltage of rectification module is continued to rise to more than or equal to the second predetermined voltage threshold, switch module Conducting, the first current constant control mould and the second constant-current control module are turned off, and the first LED string and the second LED string are connected in series, the Three constant-current control modules carry out current constant control to the first LED string and the second LED string, so that the electricity of the alternating current of input Pressure can change in the larger context, realize the application of wide input voltage.
Description of the drawings
Fig. 1 is the function structure chart of the LED linear constant-current drive circuit that the utility model first embodiment is provided;
Fig. 2 is the circuit structure diagram of the LED linear constant-current drive circuit that the utility model first embodiment is provided;
Fig. 3 is the function structure chart of the LED linear constant-current drive circuit that the utility model second embodiment is provided;
Fig. 4 is the circuit structure diagram of the LED linear constant-current drive circuit that the utility model second embodiment is provided;
Fig. 5 is the function structure chart of the LED linear constant-current drive circuit that the utility model 3rd embodiment is provided;
Fig. 6 is the circuit structure diagram of the LED linear constant-current drive circuit that the utility model 3rd embodiment is provided;
Fig. 7 is the function structure chart of the LED linear constant-current drive circuit that the utility model fourth embodiment is provided;
Fig. 8 is the circuit structure diagram of the LED linear constant-current drive circuit that the utility model fourth embodiment is provided;
Fig. 9 is between the input power of late-class circuit that the utility model embodiment is provided and the output voltage of rectification module Relation schematic diagram.
Specific embodiment
In order that the purpose of this utility model, technical scheme and advantage become more apparent, below in conjunction with accompanying drawing and enforcement Example, is further elaborated to the utility model.It should be appreciated that specific embodiment described herein is only to explain The utility model, is not used to limit the utility model.
It should be noted that term " including " in specification and claims of the present utility model and they are any Deformation, it is intended that cover non-exclusive including.Process, method or system, product for example comprising series of steps or unit Or equipment is not limited to the step of listing or unit, but alternatively also include the step of not listing or unit, or can Selection of land also includes other steps intrinsic for these processes, method, product or equipment or unit.Additionally, term " first ", " second " and " the 3rd " etc. are for distinguishing different objects, not for description particular order.
First embodiment:
Fig. 1 shows the modular structure of the LED linear constant-current drive circuit that the utility model first embodiment is provided, in order to It is easy to explanation, illustrate only the part related to the utility model embodiment, details are as follows:
As shown in figure 1, the utility model embodiment provide LED linear constant-current drive circuit and the first LED string 10 and Second LED string 20 connects, and LED linear constant-current drive circuit includes rectification module 1, the input and alternating current of rectification module 1 Source AC connects, and rectification module 1 carries out rectification to the alternating current that AC power AC is exported, and exports direct current for the first LED string 10 and second LED string 20 be powered.
Wherein, the first LED string 10 and the second LED string 20 by multiple light emitting diodes according to a upper light emitting diode The mode of the negative electrode anode that connects next light emitting diode be followed in series to form, the first LED string 10 or the second LED string 20 In first light emitting diode anode be the first LED string 10 or the second LED string 20 input, the first LED string 10 Or second last light emitting diode in LED string 20 negative electrode be the first LED string 10 or the second LED string 20 output End.In actual applications, the number of LED can phase in the number and the second LED string 10 of LED in the first LED string 10 Deng, it is also possible to unequal, i.e. the forward conduction voltage of the forward conduction voltage of the first LED string 10 and the second LED string 20 can With equal, it is also possible to unequal, it is configured with specific reference to actual conditions, is not limited herein.
LED linear constant-current drive circuit also includes that serioparallel exchange module 2, the first constant-current driven module 3, the second constant current drive Module 4, the 3rd constant-current driven module 5 and switch module 6.
The first end of serioparallel exchange module 2, the input of the 3rd constant-current control module 5 and the second constant-current control module 4 Input is connected to altogether the first output end of rectification module 1, the output end of the 3rd constant-current control module 5 and the first LED string 10 Input connect, the second end of serioparallel exchange module 2, the output end of the first constant-current driven module 3, the second LED string 20 it is defeated The second output end for going out end and rectification module 1 is connected to altogether ground, the input of the first constant-current control module 3 and the first LED string 10 Output end be connected to the input of switch module 6 altogether, the voltage input end and controlled end of the first constant-current driven module 3 respectively with string And the output end and control end connection of modular converter 2, the controlled end and output end of the second constant-current driven module 4 respectively with switching molding The input connection of the output end of block 6 and the second LED string 20.
When the output voltage of rectification module 1 reaches the forward conduction voltage of the first LED string 10 or the second LED string 20 When, the output voltage of rectification module 1 is less than or equal to the first predetermined voltage threshold, and now, switch module 6 is turned off, the first LED The LED string 20 of string 10 and second is connected in parallel, and the first constant-current control module 3 and the second constant-current control module 4 are respectively to a LED The LED string 20 of lamp string 10 and second carries out current constant control, and the 3rd constant-current control module 5 does not carry out current constant control to LED string;When The output voltage of rectification module 1 rises to more than the first predetermined voltage threshold and continues to rise and less than the second predetermined voltage threshold When, the output current of 2 pairs of the first constant-current control modules 3 of serioparallel exchange module is adjusted, and then to the input work of late-class circuit Rate carries out power limitation control;When the output voltage of rectification module 1 is continued to rise to more than or equal to the second predetermined voltage threshold, Now, switch module 6 is turned on, and the first constant-current control module 3 and the second constant-current control module 4 are turned off, the first LED string 10 and Two LED strings 20 are connected in series, and the 3rd the first LED string 10 of constant-current control module 5 pairs and the second LED string 20 carry out constant current control System.
In the utility model embodiment, late-class circuit refers specifically to include serioparallel exchange module 2, the first constant-current control module 3rd, the second constant-current control module 4, the 3rd constant-current control module 5, switch module 6, the first LED string 10 and the second LED string 20 Circuit part.
In the utility model embodiment, specifically, when the output voltage of rectification module 1 continues to rise to be more than or equal to During the second predetermined voltage threshold, serioparallel exchange module 2 controls the first constant-current control module 3 and turns off, simultaneously as the second constant current control The output voltage of molding block 4 is more than the first reference voltage, therefore, the second constant-current control module 4 is also at off state.
In the utility model embodiment, the first predetermined voltage threshold, the second predetermined voltage threshold and the 3rd predeterminated voltage Threshold value can be configured according to actual conditions, not be limited herein.
In actual applications, rectification module 1 can be bridge rectifier, or other kinds of rectification circuit, It is configured with specific reference to actual conditions, is not limited herein.
In the utility model embodiment, the magnitude of voltage of AC power AC can be 110V~220V, that is, the exchange being input into The voltage of electricity can change in 110V~220V so that LED linear constant-current drive circuit realizes the application of wide input voltage; Meanwhile, during input voltage changes, entered by the output current of 2 pairs of the first constant-current control modules 3 of serioparallel exchange module Row is adjusted, and then adjusts the power of the first LED string 10, and the input power for making late-class circuit is held essentially constant;And relative to Traditional LED linear constant-current drive circuit, the LED linear constant-current drive circuit that the utility model embodiment is provided eliminates parallel connection In the filter capacitor of the output end of rectification module 1, the power factor of circuit is improve.
Fig. 2 shows the circuit structure of the LED linear constant-current drive circuit that the utility model first embodiment is provided, in order to It is easy to explanation, illustrate only the part related to the utility model embodiment, details are as follows:
As shown in Fig. 2 used as the embodiment of the utility model one, the first constant-current control module 3 includes the first operational amplifier EA1, first switch pipe N1 and first resistor R1.
The in-phase input end of the first operational amplifier EA1 is the voltage input end of the first constant-current control module 3, the first computing The output end of amplifier EA1 and the control end of first switch pipe N1 connect altogether the controlled end as the first constant-current control module 3, and first The hot end of switching tube N1 is the input of the first constant-current control module 3, and the cold end of first switch pipe N1 is electric with first The first end of resistance R1 is connected to altogether the inverting input of the first operational amplifier EA1, and the second end of first resistor R1 is the first constant current The output end of control module 3.
In the utility model embodiment, first switch pipe N1 can be NMOS tube, the grid of NMOS tube, source electrode and drain electrode The respectively control end of first switch pipe N1, cold end and hot end.Certainly, first switch pipe N1 can also adopt three poles The switching devices such as pipe, FET are realized, are configured with specific reference to actual conditions, are not limited herein.
Used as the embodiment of the utility model one, the second constant-current driven module 4 includes that the second operational amplifier EA2, second open Close pipe N2 and second resistance;
The in-phase input end and output end of the second operational amplifier EA2 respectively with the first reference voltage source and second switch pipe The control end connection of N2, the hot end of second switch pipe N2 is the input of the second constant-current driven module 4, second switch pipe N2 The first end of cold end and second resistance R2 be connected to the inverting input of the second operational amplifier EA2, second resistance R2 altogether First end and the second end be respectively the controlled end and output end of the second constant-current driven module 4.
In the utility model embodiment, the first reference voltage source provides the first benchmark electricity for the second operational amplifier EA2 Pressure Vref.
In the utility model embodiment, second switch pipe N2 can be NMOS tube, the grid of NMOS tube, source electrode and drain electrode The respectively control end of second switch pipe N2, cold end and hot end.Certainly, second switch pipe N2 can also adopt three poles The switching devices such as pipe, FET are realized, are configured with specific reference to actual conditions, are not limited herein.
Used as the embodiment of the utility model one, the 3rd constant-current driven module 5 includes that the 3rd operational amplifier EA3, the 3rd open Close pipe N2 and 3rd resistor R3;
The in-phase input end and output end of the 3rd operational amplifier EA3 respectively with the first reference voltage source and the 3rd switching tube The control end connection of N3, the hot end of the 3rd switching tube N3 is the input of the 3rd constant-current driven module 5, the 3rd switching tube N3 The first end of cold end and 3rd resistor R3 be connected to the inverting input of the 3rd operational amplifier EA3,3rd resistor R3 altogether The second end be the 3rd constant-current driven module 5 output end.
In the utility model embodiment, the first reference voltage source also provides the first benchmark for the 3rd operational amplifier EA3 Voltage Vref.
In the utility model embodiment, the 3rd switching tube N3 can be NMOS tube, the grid of NMOS tube, source electrode and drain electrode The respectively control end of the 3rd switching tube N3, cold end and hot end.Certainly, the 3rd switching tube N3 can also adopt three poles The switching devices such as pipe, FET are realized, are configured with specific reference to actual conditions, are not limited herein.
As the embodiment of the utility model one, serioparallel exchange module 2 include the first filter capacitor C1, the 4th resistance R4, the Five resistance R5, the 6th resistance R6, the 7th resistance R7, the 4th switching tube N4, the 5th switching tube N5, the first amplifier Amp1, second Amplifier Amp2 and comparator Comp1.
Second end of the first end of the 4th resistance R4 and the 5th resistance R5 is respectively the first end of serioparallel exchange module 2 and Two ends, second end of the 4th resistance R4, the first end of the first filter capacitor C1, the in-phase input end of the first amplifier Amp1 and ratio In-phase input end compared with device Comp1 is connected to altogether the first end of the 5th resistance R5, the second end and the rectification mould of the first filter capacitor C1 The second output end connection of block 1, the control end and hot end of the 4th switching tube N4 respectively with the output of the first amplifier Amp1 End and power supply connection, the cold end of the 4th switching tube N4 and the first end of the 6th resistance R6 are connected to altogether the first amplifier Amp1's Inverting input, the second end and the first end of the 7th resistance R7 of the 6th resistance R6 are connected to altogether the anti-phase defeated of the second amplifier Amp2 Enter end, the in-phase input end of the second amplifier Amp2 is connected with the first reference voltage source, the output end of the second amplifier Amp2 and Second end of the 7th resistance R7 connects altogether the output end as serioparallel exchange module 2, the inverting input of comparator Comp1 and second Reference voltage source connects, the control end and cold end of the 5th switching tube N5 output end respectively with comparator Comp1 and rectification The second output end connection of module 1, the hot end of the 5th switching tube N5 is the control end of serioparallel exchange module 2.
In the utility model embodiment, the resistance of 3rd resistor R3 is less than the resistance of second resistance R2, and 3rd resistor The resistance of R3 less than first resistor R1 resistance, with ensure the first LED string 10 and the second LED string 20 by be connected in parallel turn It is changed to when being connected in series, second switch pipe N2 is off state, it is ensured that the second crossing current control module 4 quits work.
Used as the embodiment of the utility model one, switch module 6 is diode D1.
The anode and negative electrode of diode D1 is respectively the input and output end of switch module 6.
Relative to traditional LED linear constant-current drive circuit, the LED linear constant current that the utility model embodiment is provided drives Circuit eliminates the filter capacitor for being connected in parallel on the output end of rectification module 1, by the first filter capacitor C1 be connected to the 4th resistance R4 and Between the common port of the 5th resistance R5 and the second output end of rectification module 1 so that LED linear constant-current drive circuit can be realized High Power Factor.
The operation principle of the LED linear constant-current drive circuit that the present embodiment is provided is as follows:
As shown in Fig. 2 when the output voltage VIN of rectification module 1 reaches the first LED string 10 or the second LED string 20 During forward conduction voltage, the output voltage VIN of rectification module 1 is less than or equal to the first predetermined voltage threshold, now, rectification module 1 output voltage VIN through the 4th resistance R4 and the 5th resistance R5 partial pressure VT be less than or equal to the first reference voltage V ref, two Pole pipe D1 is turned off, and the first LED string 10 and the second LED string 20 are connected in parallel, the 4th switching tube N4 shut-offs, the first operation amplifier The voltage of the in-phase input end of device EA1 is the first reference voltage V ref.Because the resistance of 3rd resistor R3 is less than first resistor R1 Resistance, therefore, the first the first LED string of constant-current control module 3 pairs 10 carries out current constant control so that flow through the first LED string 10 electric current I1=Vref/R1, the 3rd constant-current control module 5 does not carry out current constant control to the first LED string 10;Meanwhile, second 4 pairs of the second LED strings 20 of constant-current control module carry out current constant control so that flow through the electric current I2=Vref/ of the second LED string 20 R2.By adjusting the first reference voltage V ref, first resistor R1 and the value of second resistance R2, can respectively to flowing through a LED The electric current of the LED string 20 of lamp string 10 and second is adjusted.
When the output voltage VIN of rectification module 1 is risen to more than the first predetermined voltage threshold and continues to rise and less than During two predetermined voltage thresholds, the output voltage VIN of rectification module 1 is more than through partial pressure VT of the 4th resistance R4 and the 5th resistance R5 First reference voltage V ref, the 4th switching tube N4 conductings, now, series-parallel conversion module 2 starts to the first constant-current control module 3 Input voltage be adjusted, and then the electric current I1 to flowing through the first LED string 10 is adjusted.Specifically, series-parallel conversion Module 2 is exported to the voltage of the in-phase input end of the first operational amplifier EA1Then flow through The electric current of one LED string 10With the increasing of the output voltage VIN of rectification module 1 Greatly, VT increases, output current I1 reduces, because the input power of late-class circuit is P=VIN*I1, therefore, adjust the big I of I1 So that the input power of late-class circuit is held essentially constant.
When the output voltage VIN of rectification module 1 is continued to rise to more than or equal to the second predetermined voltage threshold, rectification mould The output voltage VIN of block 1 is more than or equal to the second reference voltage V R through partial pressure VT of the 4th resistance R4 and the 5th resistance R5, this When, comparator Comp1 controls the 5th switching tube N5 conductings, and first switch pipe N1 shut-offs, the first constant-current driven module 3 stops work Make, diode D1 conductings, by the output voltage VIN of adjustment rectification module 1, the value of the 4th resistance R4 and the 5th resistance R5, make Obtain VT>During VR, the output voltage VIN of rectification module 1 reaches conducting voltage of the first LED string 10 plus the second LED string 20, Now, the first LED string 10 and the second LED string 20 are connected in series, the 3rd He of the first LED string 10 of constant-current control module 5 pairs Second LED string 20 carries out current constant control so that flow through the electric current I3=Vref/ of the first LED string 10 and the second LED string 20 R3.Because the resistance of 3rd resistor R3 is less than the resistance of second resistance R2 so that cold end (second fortune of second switch pipe N2 Calculate amplifier EA2 in-phase input end) voltage be more than the first reference voltage V ref, therefore, the second operational amplifier EA2 output Low level, second switch pipe N2 shut-offs, the second constant-current control module 4 quits work.
From fig. 9, it can be seen that the change of the output voltage VIN with rectification module 1, the input power of late-class circuit is basic Keep constant, so that the voltage of input AC electricity can change in a larger scope, and ensure that late-class circuit Input power be basically unchanged, while realizing High Power Factor.
Second embodiment:
Fig. 3 shows the modular structure of the LED linear constant-current drive circuit that the utility model second embodiment is provided, the reality It is on the basis of first embodiment, corresponding adjustment have been carried out to the annexation of the 3rd constant-current control module 5, in order to just to apply example In explanation, the part related to the utility model embodiment is illustrate only, details are as follows:
As shown in figure 3, the utility model embodiment provide LED linear constant-current drive circuit and the first LED string 10 and Second LED string 20 connects, and LED linear constant-current drive circuit includes rectification module 1, the input and alternating current of rectification module 1 Source AC connects, and rectification module 1 carries out rectification to the alternating current that AC power AC is exported, and exports direct current for the first LED string 10 and second LED string 20 be powered.
Wherein, the first LED string 10 and the second LED string 20 by multiple light emitting diodes according to a upper light emitting diode The mode of the negative electrode anode that connects next light emitting diode be followed in series to form, the first LED string 10 or the second LED string 20 In first light emitting diode anode be the first LED string 10 or the second LED string 20 input, the first LED string 10 Or second last light emitting diode in LED string 20 negative electrode be the first LED string 10 or the second LED string 20 output End.In actual applications, the number of LED can phase in the number and the second LED string 10 of LED in the first LED string 10 Deng, it is also possible to unequal, i.e. the forward conduction voltage of the forward conduction voltage of the first LED string 10 and the second LED string 20 can With equal, it is also possible to unequal, it is configured with specific reference to actual conditions, is not limited herein.
LED linear constant-current drive circuit also includes that serioparallel exchange module 2, the first constant-current driven module 3, the second constant current drive Module 4, the 3rd constant-current driven module 5 and switch module 6.
The input of the first end of serioparallel exchange module 2, the input of the first LED string 10 and the second constant-current control module 4 End is connected to altogether the first output end of rectification module 1, the second end of serioparallel exchange module 2, the output of the first constant-current driven module 3 Second output end of end, the output end of the 3rd constant-current control module 5 and rectification module 1 is connected to altogether ground, the first constant-current control module 3 Input and the output end of the first LED string 10 be connected to the input of switch module 6, the electricity of the first constant-current driven module 3 altogether Pressure input and controlled end are respectively connected with the output end and control end of serioparallel exchange module 2, and the second constant-current driven module 4 is received Control end and output end are connected respectively with the output end of switch module 6 and the input of the second LED string 20, the second LED string 20 Output end be connected with the input of the 3rd constant-current control module 5.
When the output voltage of rectification module 1 reaches the forward conduction voltage of the first LED string 10 or the second LED string 20 When, the output voltage of rectification module 1 is less than or equal to the first predetermined voltage threshold, and now, switch module 6 is turned off, the first LED The LED string 20 of string 10 and second is connected in parallel, and the first constant-current control module 3 and the second constant-current control module 4 are respectively to a LED The LED string 20 of lamp string 10 and second carries out current constant control, and the 3rd constant-current control module 5 does not carry out current constant control to LED string;When The output voltage of rectification module 1 rises to more than the first predetermined voltage threshold and continues to rise and less than the second predetermined voltage threshold When, the output current of 2 pairs of the first constant-current control modules 3 of serioparallel exchange module is adjusted, and then to the input work of late-class circuit Rate carries out power limitation control;When the output voltage of rectification module 1 is continued to rise to more than or equal to the second predetermined voltage threshold, Now, switch module 6 is turned on, and the first constant-current control module 3 and the second constant-current control module 4 are turned off, the first LED string 10 and Two LED strings 20 are connected in series, and the 3rd the first LED string 10 of constant-current control module 5 pairs and the second LED string 20 carry out constant current control System.
In the utility model embodiment, late-class circuit refers specifically to include serioparallel exchange module 2, the first constant-current control module 3rd, the second constant-current control module 4, the 3rd constant-current control module 5, switch module 6, the first LED string 10 and the second LED string 20 Circuit part.
In the utility model embodiment, specifically, when the output voltage of rectification module 1 continues to rise to be more than or equal to During the second predetermined voltage threshold, serioparallel exchange module 2 controls the first constant-current control module 3 and turns off, simultaneously as the second constant current control The output voltage of molding block is more than the first reference voltage, therefore, the second constant-current control module is also at off state.
In the utility model embodiment, the first predetermined voltage threshold, the second predetermined voltage threshold and the 3rd predeterminated voltage Threshold value can be configured according to actual conditions, not be limited herein.
In actual applications, rectification module 1 can be bridge rectifier, or other kinds of rectification circuit, It is configured with specific reference to actual conditions, is not limited herein.
In the utility model embodiment, the magnitude of voltage of AC power AC can be 110V~220V, that is, the exchange being input into The voltage of electricity can change in 110V~220V so that LED linear constant-current drive circuit realizes the application of wide input voltage; Meanwhile, during input voltage changes, entered by the output current of 2 pairs of the first constant-current control modules 3 of serioparallel exchange module Row is adjusted, and then adjusts the power of the first LED string 10, and the input power for making late-class circuit is held essentially constant;And relative to Traditional LED linear constant-current drive circuit, the LED linear constant-current drive circuit that the utility model embodiment is provided eliminates parallel connection In the filter capacitor of the output end of rectification module 1, the power factor of circuit is improve.
Fig. 4 shows the circuit structure of the LED linear constant-current drive circuit that the utility model second embodiment is provided, in order to It is easy to explanation, illustrate only the part related to the utility model embodiment, details are as follows:
As shown in figure 4, the present embodiment provide LED linear constant-current drive circuit in modules circuit structure with one reality The circuit structure for applying modules in the LED linear constant-current drive circuit of example offer is identical, specifically refer to Fig. 2 and figure Associated description in 2 corresponding first embodiments, here is omitted.
The operation principle of the LED linear constant-current drive circuit that the present embodiment is provided is as follows:
As shown in figure 4, when the output voltage VIN of rectification module 1 reaches the first LED string 10 or the second LED string 20 During forward conduction voltage, the output voltage VIN of rectification module 1 is less than or equal to the first predetermined voltage threshold, now, rectification module 1 output voltage VIN through the 4th resistance R4 and the 5th resistance R5 partial pressure VT be less than or equal to the first reference voltage V ref, two Pole pipe D1 is turned off, and the first LED string 10 and the second LED string 20 are connected in parallel, the 4th switching tube N4 shut-offs, the first operation amplifier The voltage of the in-phase input end of device EA1 is the first reference voltage V ref.First the first LED string 10 of constant-current control module 3 pairs enters Row current constant control so that flow through the electric current I1=Vref/R1 of the first LED string 10;Simultaneously as the resistance of 3rd resistor R3 is little In the resistance of first resistor R1, therefore, the second the second LED string of constant-current control module 4 pairs 20 carries out current constant control so that flow through The electric current I2=Vref/R2 of the second LED string 20, the 3rd constant-current control module 5 does not carry out constant current control to the second LED string 20 System.By adjusting the first reference voltage V ref, first resistor R1 and the value of second resistance R2, can respectively to flowing through a LED The electric current of the LED string 20 of lamp string 10 and second is adjusted.
When the output voltage VIN of rectification module 1 is risen to more than the first predetermined voltage threshold and continues to rise and less than During two predetermined voltage thresholds, the output voltage VIN of rectification module 1 is more than through partial pressure VT of the 4th resistance R4 and the 5th resistance R5 First reference voltage V ref, the 4th switching tube N4 conductings, now, series-parallel conversion module 2 starts to the first constant-current control module 3 Input voltage be adjusted, and then the electric current I1 to flowing through the first LED string 10 is adjusted.Specifically, series-parallel conversion Module 2 is exported to the voltage of the in-phase input end of the first operational amplifier EA1Then flow through The electric current of one LED string 10With the increasing of the output voltage VIN of rectification module 1 Greatly, VT increases, output current I1 reduces, because the input power of late-class circuit is P=VIN*I1, therefore, adjust the big I of I1 So that the input power of late-class circuit is held essentially constant.
When the output voltage VIN of rectification module 1 is continued to rise to more than or equal to the second predetermined voltage threshold, rectification mould The output voltage VIN of block 1 is more than or equal to the second reference voltage V R through partial pressure VT of the 4th resistance R4 and the 5th resistance R5, this When, comparator Comp1 controls the 5th switching tube N5 conductings, and first switch pipe N1 shut-offs, the first constant-current driven module 3 stops work Make, diode D1 conductings, by the output voltage VIN of adjustment rectification module 1, the value of the 4th resistance R4 and the 5th resistance R5, make Obtain VT>During VR, the output voltage VIN of rectification module 1 reaches conducting voltage of the first LED string 10 plus the second LED string 20, Now, the first LED string 10 and the second LED string 20 are connected in series, the 3rd He of the first LED string 10 of constant-current control module 5 pairs Second LED string 20 carries out current constant control so that flow through the electric current I3=Vref/ of the first LED string 10 and the second LED string 20 R3.Because the resistance of 3rd resistor R3 is less than the resistance of second resistance R2 so that cold end (second fortune of second switch pipe N2 Calculate amplifier EA2 in-phase input end) voltage be more than the first reference voltage V ref, therefore, the second operational amplifier EA2 output Low level, second switch pipe N2 shut-offs, the second constant-current control module 4 quits work.
From fig. 9, it can be seen that the change of the output voltage VIN with rectification module 1, the input power of late-class circuit is basic Keep constant, so that the voltage of input AC electricity can change in a larger scope, and ensure that late-class circuit Input power be basically unchanged, while realizing High Power Factor.
3rd embodiment:
Fig. 5 shows the modular structure of the LED linear constant-current drive circuit that the utility model 3rd embodiment is provided, in order to It is easy to explanation, illustrate only the part related to the utility model embodiment, details are as follows:
As shown in figure 5, the utility model embodiment provide LED linear constant-current drive circuit and the first LED string 10 and Second LED string 20 connects, and LED linear constant-current drive circuit includes the filter capacitor C2 of rectification module 1 and second, rectification module 1 Input be connected with AC power AC, the first end of the second filter capacitor C2 and the second end are respectively with the first of rectification module 1 Output end and the second output end connect, and the filter capacitor C2 of rectification module 1 and second is respectively to the alternating current of AC power AC output Rectification and filtering process are carried out, and it is that the first LED string 10 and the second LED string 20 are powered to export direct current.
Wherein, the first LED string 10 and the second LED string 20 by multiple light emitting diodes according to a upper light emitting diode The mode of the negative electrode anode that connects next light emitting diode be followed in series to form, the first LED string 10 or the second LED string 20 In first light emitting diode anode be the first LED string 10 or the second LED string 20 input, the first LED string 10 Or second last light emitting diode in LED string 20 negative electrode be the first LED string 10 or the second LED string 20 output End.In actual applications, the number of LED can phase in the number and the second LED string 10 of LED in the first LED string 10 Deng, it is also possible to unequal, i.e. the forward conduction voltage of the forward conduction voltage of the first LED string 10 and the second LED string 20 can With equal, it is also possible to unequal, it is configured with specific reference to actual conditions, is not limited herein.
LED linear constant-current drive circuit also includes that serioparallel exchange module 2, the first constant-current driven module 3, the second constant current drive Module 4, the 3rd constant-current driven module 5 and switch module 6.
The first end of serioparallel exchange module 2, the input of the 3rd constant-current control module 5 and the second constant-current control module 4 Input is connected to altogether the first output end of rectification module 1, the output end of the 3rd constant-current control module 5 and the first LED string 10 Input connect, the second end of serioparallel exchange module 2, the output end of the first constant-current driven module 3, the second LED string 20 it is defeated The second output end for going out end and rectification module 1 is connected to altogether ground, the input of the first constant-current control module 3 and the first LED string 10 Output end be connected to the input of switch module 6 altogether, the voltage input end and controlled end of the first constant-current driven module 3 respectively with string And the output end and control end connection of modular converter 2, the controlled end and output end of the second constant-current driven module 4 respectively with switching molding The input connection of the output end of block 6 and the second LED string 20.
When the output voltage of rectification module 1 reaches the forward conduction voltage of the first LED string 10 or the second LED string 20 When, the output voltage of rectification module 1 is less than or equal to the first predetermined voltage threshold, and now, switch module 6 is turned off, the first LED The LED string 20 of string 10 and second is connected in parallel, and the first constant-current control module 3 and the second constant-current control module 4 are respectively to a LED The LED string 20 of lamp string 10 and second carries out current constant control, and the 3rd constant-current control module 5 does not carry out current constant control to LED string;When The output voltage of rectification module 1 rises to more than the first predetermined voltage threshold and continues to rise and less than the second predetermined voltage threshold When, the output current of 2 pairs of the first constant-current control modules 3 of serioparallel exchange module is adjusted, and then to the input work of late-class circuit Rate carries out power limitation control;When the output voltage of rectification module 1 is continued to rise to more than or equal to the second predetermined voltage threshold, Now, switch module 6 is turned on, and the first constant-current control module 3 and the second constant-current control module 4 are turned off, the first LED string 10 and Two LED strings 20 are connected in series, and the 3rd the first LED string 10 of constant-current control module 5 pairs and the second LED string 20 carry out constant current control System.
In the utility model embodiment, late-class circuit refers specifically to include serioparallel exchange module 2, the first constant-current control module 3rd, the second constant-current control module 4, the 3rd constant-current control module 5, switch module 6, the first LED string 10 and the second LED string 20 Circuit part.
In the utility model embodiment, specifically, when the output voltage of rectification module 1 continues to rise to be more than or equal to During the second predetermined voltage threshold, serioparallel exchange module 2 controls the first constant-current control module 3 and turns off, simultaneously as the second constant current control The output voltage of molding block is more than the first reference voltage, therefore, the second constant-current control module is also at off state.
In the utility model embodiment, the first predetermined voltage threshold, the second predetermined voltage threshold and the 3rd predeterminated voltage Threshold value can be configured according to actual conditions, not be limited herein.
In actual applications, rectification module 1 can be bridge rectifier, or other kinds of rectification circuit, It is configured with specific reference to actual conditions, is not limited herein.
In the utility model embodiment, the magnitude of voltage of AC power AC can be 110V~220V, that is, the exchange being input into The voltage of electricity can change in 110V~220V so that LED linear constant-current drive circuit realizes the application of wide input voltage; Meanwhile, during input voltage changes, entered by the output current of 2 pairs of the first constant-current control modules 3 of serioparallel exchange module Row is adjusted, and then adjusts the power of the first LED string 10, and the input power for making late-class circuit is held essentially constant;And this enforcement LED linear constant-current drive circuit that example is provided can make first in the output end second filter capacitor C2 in parallel of rectification module 1 The LED string 20 of LED string 10 and second is realized without stroboscopic.
Fig. 6 shows the circuit structure of the LED linear constant-current drive circuit that the utility model 3rd embodiment is provided, in order to It is easy to explanation, illustrate only the part related to the utility model embodiment, details are as follows:
As shown in fig. 6, the present embodiment provide LED linear constant-current drive circuit in modules circuit structure with one reality The circuit structure for applying modules in the LED linear constant-current drive circuit of example offer is identical, specifically refer to Fig. 2 and figure Associated description in 2 corresponding first embodiments, here is omitted.
The operation principle of the LED linear constant-current drive circuit that the present embodiment is provided is as follows:
As shown in fig. 6, when the output voltage VIN of rectification module 1 reaches the first LED string 10 or the second LED string 20 During forward conduction voltage, the output voltage VIN of rectification module 1 is less than or equal to the first predetermined voltage threshold, now, rectification module 1 output voltage VIN through the 4th resistance R4 and the 5th resistance R5 partial pressure VT be less than or equal to the first reference voltage V ref, two Pole pipe D1 is turned off, and the first LED string 10 and the second LED string 20 are connected in parallel, the 4th switching tube N4 shut-offs, the first operation amplifier The voltage of the in-phase input end of device EA1 is the first reference voltage V ref.Because the resistance of 3rd resistor R3 is less than first resistor R1 Resistance, therefore, the first the first LED string of constant-current control module 3 pairs 10 carries out current constant control so that flow through the first LED string 10 electric current I1=Vref/R1, the 3rd constant-current control module 5 does not carry out current constant control to the first LED string 10;Meanwhile, second 4 pairs of the second LED strings 20 of constant-current control module carry out current constant control so that flow through the electric current I2=Vref/ of the second LED string 20 R2.By adjusting the first reference voltage V ref, first resistor R1 and the value of second resistance R2, can respectively to flowing through a LED The electric current of the LED string 20 of lamp string 10 and second is adjusted.
When the output voltage VIN of rectification module 1 is risen to more than the first predetermined voltage threshold and continues to rise and less than During two predetermined voltage thresholds, the output voltage VIN of rectification module 1 is more than through partial pressure VT of the 4th resistance R4 and the 5th resistance R5 First reference voltage V ref, the 4th switching tube N4 conductings, now, series-parallel conversion module 2 starts to the first constant-current control module 3 Input voltage be adjusted, and then the electric current I1 to flowing through the first LED string 10 is adjusted.Specifically, series-parallel conversion Module 2 is exported to the voltage of the in-phase input end of the first operational amplifier EA1Then flow through The electric current of one LED string 10With the increasing of the output voltage VIN of rectification module 1 Greatly, VT increases, output current I1 reduces, because the input power of late-class circuit is P=VIN*I1, therefore, adjust the big I of I1 So that the input power of late-class circuit is held essentially constant.
When the output voltage VIN of rectification module 1 is continued to rise to more than or equal to the second predetermined voltage threshold, rectification mould The output voltage VIN of block 1 is more than or equal to the second reference voltage V R through partial pressure VT of the 4th resistance R4 and the 5th resistance R5, this When, comparator Comp1 controls the 5th switching tube N5 conductings, and first switch pipe N1 shut-offs, the first constant-current driven module 3 stops work Make, diode D1 conductings, by the output voltage VIN of adjustment rectification module 1, the value of the 4th resistance R4 and the 5th resistance R5, make Obtain VT>During VR, the output voltage VIN of rectification module 1 reaches conducting voltage of the first LED string 10 plus the second LED string 20, Now, the first LED string 10 and the second LED string 20 are connected in series, the 3rd He of the first LED string 10 of constant-current control module 5 pairs Second LED string 20 carries out current constant control so that flow through the electric current I3=Vref/ of the first LED string 10 and the second LED string 20 R3.Because the resistance of 3rd resistor R3 is less than the resistance of second resistance R2 so that cold end (second fortune of second switch pipe N2 Calculate amplifier EA2 in-phase input end) voltage be more than the first reference voltage V ref, therefore, the second operational amplifier EA2 output Low level, second switch pipe N2 shut-offs, the second constant-current control module 4 quits work.
From fig. 9, it can be seen that the change of the output voltage VIN with rectification module 1, the input power of late-class circuit is basic Keep constant, so that the voltage of input AC electricity can change in a larger scope, and ensure that late-class circuit Input power be basically unchanged, while the first LED string 10 and the second LED string 20 can be made to realize without stroboscopic.
Fourth embodiment:
Fig. 7 shows the modular structure of the LED linear constant-current drive circuit that the utility model fourth embodiment is provided, the reality It is on the basis of 3rd embodiment, corresponding adjustment have been carried out to the annexation of the 3rd constant-current control module 5, in order to just to apply example In explanation, the part related to the utility model embodiment is illustrate only, details are as follows:
As shown in fig. 7, the utility model embodiment provide LED linear constant-current drive circuit and the first LED string 10 and Second LED string 20 connects, and LED linear constant-current drive circuit includes the filter capacitor C2 of rectification module 1 and second, rectification module 1 Input be connected with AC power AC, the first end of the second filter capacitor C2 and the second end are respectively with the first of rectification module 1 Output end and the second output end connect, and the filter capacitor C2 of rectification module 1 and second is respectively to the alternating current of AC power AC output Rectification and filtering process are carried out, and it is that the first LED string 10 and the second LED string 20 are powered to export direct current.
Wherein, the first LED string 10 and the second LED string 20 by multiple light emitting diodes according to a upper light emitting diode The mode of the negative electrode anode that connects next light emitting diode be followed in series to form, the first LED string 10 or the second LED string 20 In first light emitting diode anode be the first LED string 10 or the second LED string 20 input, the first LED string 10 Or second last light emitting diode in LED string 20 negative electrode be the first LED string 10 or the second LED string 20 output End.In actual applications, the number of LED can phase in the number and the second LED string 10 of LED in the first LED string 10 Deng, it is also possible to unequal, i.e. the forward conduction voltage of the forward conduction voltage of the first LED string 10 and the second LED string 20 can With equal, it is also possible to unequal, it is configured with specific reference to actual conditions, is not limited herein.
LED linear constant-current drive circuit also includes that serioparallel exchange module 2, the first constant-current driven module 3, the second constant current drive Module 4, the 3rd constant-current driven module 5 and switch module 6.
The input of the first end of serioparallel exchange module 2, the input of the first LED string 10 and the second constant-current control module 4 End is connected to altogether the first output end of rectification module 1, the second end of serioparallel exchange module 2, the output of the first constant-current driven module 3 Second output end of end, the output end of the 3rd constant-current control module 5 and rectification module 1 is connected to altogether ground, the first constant-current control module 3 Input and the output end of the first LED string 10 be connected to the input of switch module 6, the electricity of the first constant-current driven module 3 altogether Pressure input and controlled end are respectively connected with the output end and control end of serioparallel exchange module 2, and the second constant-current driven module 4 is received Control end and output end are connected respectively with the output end of switch module 6 and the input of the second LED string 20, the second LED string 20 Output end be connected with the input of the 3rd constant-current control module 5.
When the output voltage of rectification module 1 reaches the forward conduction voltage of the first LED string 10 or the second LED string 20 When, the output voltage of rectification module 1 is less than or equal to the first predetermined voltage threshold, and now, switch module 6 is turned off, the first LED The LED string 20 of string 10 and second is connected in parallel, and the first constant-current control module 3 and the second constant-current control module 4 are respectively to a LED The LED string 20 of lamp string 10 and second carries out current constant control, and the 3rd constant-current control module 5 does not carry out current constant control to LED string;When The output voltage of rectification module 1 rises to more than the first predetermined voltage threshold and continues to rise and less than the second predetermined voltage threshold When, the output current of 2 pairs of the first constant-current control modules 3 of serioparallel exchange module is adjusted, and then to the input work of late-class circuit Rate carries out power limitation control;When the output voltage of rectification module 1 is continued to rise to more than or equal to the second predetermined voltage threshold, Now, switch module 6 is turned on, and the first constant-current control module 3 and the second constant-current control module 4 are turned off, the first LED string 10 and Two LED strings 20 are connected in series, and the 3rd the first LED string 10 of constant-current control module 5 pairs and the second LED string 20 carry out constant current control System.
In the utility model embodiment, late-class circuit refers specifically to include serioparallel exchange module 2, the first constant-current control module 3rd, the second constant-current control module 4, the 3rd constant-current control module 5, switch module 6, the first LED string 10 and the second LED string 20 Circuit part.
In the utility model embodiment, specifically, when the output voltage of rectification module 1 continues to rise to be more than or equal to During the second predetermined voltage threshold, serioparallel exchange module 2 controls the first constant-current control module 3 and turns off, simultaneously as the second constant current control The output voltage of molding block is more than the first reference voltage, therefore, the second constant-current control module is also at off state.
In the utility model embodiment, the first predetermined voltage threshold, the second predetermined voltage threshold and the 3rd predeterminated voltage Threshold value can be configured according to actual conditions, not be limited herein.
In actual applications, rectification module 1 can be bridge rectifier, or other kinds of rectification circuit, It is configured with specific reference to actual conditions, is not limited herein.
In the utility model embodiment, the magnitude of voltage of AC power AC can be 110V~220V, that is, the exchange being input into The voltage of electricity can change in 110V~220V so that LED linear constant-current drive circuit realizes the application of wide input voltage; Meanwhile, during input voltage changes, entered by the output current of 2 pairs of the first constant-current control modules 3 of serioparallel exchange module Row is adjusted, and then adjusts the power of the first LED string 10, and the input power for making late-class circuit is held essentially constant;And this enforcement LED linear constant-current drive circuit that example is provided can make first in the output end second filter capacitor C2 in parallel of rectification module 1 The LED string 20 of LED string 10 and second is realized without stroboscopic.
Fig. 8 shows the circuit structure of the LED linear constant-current drive circuit that the utility model fourth embodiment is provided, in order to It is easy to explanation, illustrate only the part related to the utility model embodiment, details are as follows:
As shown in figure 8, the present embodiment provide LED linear constant-current drive circuit in modules circuit structure with one reality The circuit structure for applying modules in the LED linear constant-current drive circuit of example offer is identical, specifically refer to Fig. 2 and figure Associated description in 2 corresponding first embodiments, here is omitted.
The operation principle of the LED linear constant-current drive circuit that the present embodiment is provided is as follows:
As shown in figure 8, when the output voltage VIN of rectification module 1 reaches the first LED string 10 or the second LED string 20 During forward conduction voltage, the output voltage VIN of rectification module 1 is less than or equal to the first predetermined voltage threshold, now, rectification module 1 output voltage VIN through the 4th resistance R4 and the 5th resistance R5 partial pressure VT be less than or equal to the first reference voltage V ref, two Pole pipe D1 is turned off, and the first LED string 10 and the second LED string 20 are connected in parallel, the 4th switching tube N4 shut-offs, the first operation amplifier The voltage of the in-phase input end of device EA1 is the first reference voltage V ref.First the first LED string 10 of constant-current control module 3 pairs enters Row current constant control so that flow through the electric current I1=Vref/R1 of the first LED string 10;Simultaneously as the resistance of 3rd resistor R3 is little In the resistance of first resistor R1, therefore, the second the second LED string of constant-current control module 4 pairs 20 carries out current constant control so that flow through The electric current I2=Vref/R2 of the second LED string 20, the 3rd constant-current control module 5 does not carry out constant current control to the second LED string 20 System.By adjusting the first reference voltage V ref, first resistor R1 and the value of second resistance R2, can respectively to flowing through a LED The electric current of the LED string 20 of lamp string 10 and second is adjusted.
When the output voltage VIN of rectification module 1 is risen to more than the first predetermined voltage threshold and continues to rise and less than During two predetermined voltage thresholds, the output voltage VIN of rectification module 1 is more than through partial pressure VT of the 4th resistance R4 and the 5th resistance R5 First reference voltage V ref, the 4th switching tube N4 conductings, now, series-parallel conversion module 2 starts to the first constant-current control module 3 Input voltage be adjusted, and then the electric current I1 to flowing through the first LED string 10 is adjusted.Specifically, series-parallel conversion Module 2 is exported to the voltage of the in-phase input end of the first operational amplifier EA1Then flow through The electric current of one LED string 10With the increasing of the output voltage VIN of rectification module 1 Greatly, VT increases, output current I1 reduces, because the input power of late-class circuit is P=VIN*I1, therefore, adjust the big I of I1 So that the input power of late-class circuit is held essentially constant.
When the output voltage VIN of rectification module 1 is continued to rise to more than or equal to the second predetermined voltage threshold, rectification mould The output voltage VIN of block 1 is more than or equal to the second reference voltage V R through partial pressure VT of the 4th resistance R4 and the 5th resistance R5, this When, comparator Comp1 controls the 5th switching tube N5 conductings, and first switch pipe N1 shut-offs, the first constant-current driven module 3 stops work Make, diode D1 conductings, by the output voltage VIN of adjustment rectification module 1, the value of the 4th resistance R4 and the 5th resistance R5, make Obtain VT>During VR, the output voltage VIN of rectification module 1 reaches conducting voltage of the first LED string 10 plus the second LED string 20, Now, the first LED string 10 and the second LED string 20 are connected in series, the 3rd He of the first LED string 10 of constant-current control module 5 pairs Second LED string 20 carries out current constant control so that flow through the electric current I3=Vref/ of the first LED string 10 and the second LED string 20 R3.Because the resistance of 3rd resistor R3 is less than the resistance of second resistance R2 so that cold end (second fortune of second switch pipe N2 Calculate amplifier EA2 in-phase input end) voltage be more than the first reference voltage V ref, therefore, the second operational amplifier EA2 output Low level, second switch pipe N2 shut-offs, the second constant-current control module 4 quits work.
From fig. 9, it can be seen that the change of the output voltage VIN with rectification module 1, the input power of late-class circuit is basic Keep constant, so that the voltage of input AC electricity can change in a larger scope, and ensure that late-class circuit Input power be basically unchanged, while the first LED string 10 and the second LED string 20 can be made to realize without stroboscopic.
The utility model embodiment additionally provides a kind of LED light device, is connected with AC power, and including a LED Lamp string and the second LED string, LED light device also includes the LED linear constant-current drive circuit that any of the above-described embodiment is provided.
The LED linear constant-current drive circuit that the utility model embodiment is provided include rectification module, serioparallel exchange module, the One constant-current driven module, the second constant-current driven module, the 3rd constant-current driven module and switch module;When the output electricity of rectification module When pressure is less than or equal to the first predetermined voltage threshold, switch module is turned off, and the first LED string and the second LED connection in series-parallel connect, First constant-current control module and the second constant-current control module carry out current constant control to the first LED string and the second LED string respectively; When the output voltage of rectification module is risen to more than the first predetermined voltage threshold and continues to rise and less than the second predeterminated voltage threshold During value, serioparallel exchange module is adjusted to the output current of the first constant-current control module, and then to the input work of late-class circuit Rate carries out power limitation control;When the output voltage of rectification module is continued to rise to more than or equal to the second predetermined voltage threshold, Switch module conducting, the first current constant control mould and the shut-off of the second constant-current control module, the first LED string and the second LED string string Connection connection, the 3rd constant-current control module carries out current constant control to the first LED string and the second LED string, so that input The voltage of alternating current can change in the larger context, realize the application of wide input voltage.
Preferred embodiment of the present utility model is the foregoing is only, it is all at this not to limit the utility model Any modification, equivalent and improvement made within the spirit and principle of utility model etc., should be included in the utility model Protection domain within.

Claims (10)

1. a kind of LED linear constant-current drive circuit, connects, the LED linear constant current with the first LED string and the second LED series winding Drive circuit includes rectification module, and the rectification module carries out rectification to alternating current, and exports direct current for first LED String and the second LED string are powered, it is characterised in that the LED linear constant-current drive circuit also includes serioparallel exchange Module, the first constant-current driven module, the second constant-current driven module, the 3rd constant-current driven module and switch module;
The first end of the serioparallel exchange module, the input of the 3rd constant-current control module and the second current constant control mould The input of block is connected to altogether the first output end of the rectification module, the output end of the 3rd constant-current control module and described One LED string input connection, the second end of the serioparallel exchange module, the output end of first constant-current driven module, The output end of the second LED string and the second output end of the rectification module are connected to altogether ground, the first current constant control mould The input of block is connected to altogether the input of the switch module with the output end of the first LED string, and first constant current is driven The voltage input end and controlled end of dynamic model block is connected respectively with the output end and control end of the serioparallel exchange module, and described second The controlled end and output end of constant-current driven module respectively with the input of the output end of the switch module and the second LED string End connection;
When the output voltage of the rectification module is less than or equal to the first predetermined voltage threshold, the switch module shut-off, institute State the first LED string and the second LED connection in series-parallel connection, first constant-current control module and second current constant control Module carries out current constant control to the first LED string and the second LED string respectively;When the output electricity of the rectification module Pressure rises to more than the first predetermined voltage threshold and continues to rise and during less than the second predetermined voltage threshold, the serioparallel exchange mould Block is adjusted to the output current of first constant-current control module, and then the input power to late-class circuit carries out invariable power Control;When the output voltage of the rectification module is continued to rise to more than or equal to the second predetermined voltage threshold, the switch Module is turned on, and the first current constant control mould and second constant-current control module are turned off, the first LED string and described the Two LED strings are connected in series, and the 3rd constant-current control module is carried out to the first LED string and the second LED string Current constant control.
2. LED linear constant-current drive circuit as claimed in claim 1, it is characterised in that the first constant-current control module bag Include the first operational amplifier, first switch pipe and first resistor;
The in-phase input end of first operational amplifier is the voltage input end of first constant-current control module, described first The output end of operational amplifier is connect altogether as the controlled of first constant-current control module with the control end of the first switch pipe End, the hot end of the first switch pipe is the input of first constant-current control module, the first switch pipe it is low Potential end is connected to altogether the inverting input of first operational amplifier, the first resistor with the first end of the first resistor The second end be first constant-current control module output end.
3. LED linear constant-current drive circuit as claimed in claim 1, it is characterised in that the second constant-current driven module bag Include the second operational amplifier, second switch pipe and second resistance;
The in-phase input end and output end of second operational amplifier respectively with the first reference voltage source and the second switch The control end connection of pipe, the hot end of the second switch pipe is the input of second constant-current driven module, described the The cold end of two switching tubes is connected to altogether the inverting input of second operational amplifier with the first end of the second resistance, The first end of the second resistance and the second end are respectively the controlled end and output end of second constant-current driven module.
4. LED linear constant-current drive circuit as claimed in claim 1, it is characterised in that the 3rd constant-current driven module bag Include the 3rd operational amplifier, the 3rd switching tube and 3rd resistor;
The in-phase input end and output end of the 3rd operational amplifier is switched respectively with the first reference voltage source and the described 3rd The control end connection of pipe, the hot end of the 3rd switching tube is the input of the 3rd constant-current driven module, described the The cold end of three switching tubes is connected to altogether the inverting input of the 3rd operational amplifier with the first end of the 3rd resistor, Second end of the 3rd resistor is the output end of the 3rd constant-current driven module.
5. LED linear constant-current drive circuit as claimed in claim 1, it is characterised in that the serioparallel exchange module includes the One filter capacitor, the 4th resistance, the 5th resistance, the 6th resistance, the 7th resistance, the 4th switching tube, the 5th switching tube, first are amplified Device, the second amplifier and comparator;
The first end of the 4th resistance and the second end of the 5th resistance are respectively the first end of the serioparallel exchange module With the second end, the second end of the 4th resistance, the first end of first filter capacitor, first amplifier homophase it is defeated The in-phase input end for entering end and the comparator is connected to altogether the first end of the 5th resistance, and the second of first filter capacitor End is connected with the second output end of the rectification module, and the control end and hot end of the 4th switching tube are respectively with described the The output end of one amplifier and power supply connect, and cold end and the first end of the 6th resistance of the 4th switching tube connect altogether In the inverting input of first amplifier, the second end and the first end of the 7th resistance of the 6th resistance are connected to altogether The inverting input of second amplifier, the in-phase input end of second amplifier is connected with the first reference voltage source, institute The output end and the second end of the 7th resistance of stating the second amplifier meet altogether the output end as the serioparallel exchange module, institute The inverting input for stating comparator is connected with the second reference voltage source, and the control end of the 5th switching tube and cold end are distinguished It is connected with the output end of the comparator and the second output end of the rectification module, the hot end of the 5th switching tube is The control end of the serioparallel exchange module.
6. LED linear constant-current drive circuit as claimed in claim 1, it is characterised in that the switch module is diode;
The anode and negative electrode of the diode is respectively the input and output end of the switch module.
7. LED linear constant-current drive circuit as claimed in claim 1, it is characterised in that the LED linear constant-current drive circuit Also include the second filter capacitor;
The first end of second filter capacitor and the second end export respectively with first output end and second of the rectification module End connection.
8. LED linear constant-current drive circuit as claimed in claim 7, it is characterised in that the serioparallel exchange module includes the Four resistance, the 5th resistance, the 6th resistance, the 7th resistance, the 4th switching tube, the 5th switching tube, the first amplifier, the second amplifier And comparator;
The first end of the 4th resistance and the second end of the 5th resistance are respectively the first end of the serioparallel exchange module With the second end, the homophase at second end, the in-phase input end of first amplifier and the comparator of the 4th resistance is defeated Enter end and be connected to the first end of the 5th resistance altogether, the control end and hot end of the 4th switching tube are respectively with described first The output end of amplifier and power supply connect, and cold end and the first end of the 6th resistance of the 4th switching tube are connected to altogether The inverting input of first amplifier, the second end and the first end of the 7th resistance of the 6th resistance are connected to altogether institute The inverting input of the second amplifier is stated, the in-phase input end of second amplifier is connected with the first reference voltage source, described The output end of the second amplifier connects altogether the output end as the serioparallel exchange module with the second end of the 7th resistance, described The inverting input of comparator is connected with the second reference voltage source, the control end and cold end of the 5th switching tube respectively with The second output end connection of the output end of the comparator and the rectification module, the hot end of the 5th switching tube is institute State the control end of serioparallel exchange module.
9. a kind of LED linear constant-current drive circuit, connects, the LED linear constant current with the first LED string and the second LED series winding Drive circuit includes rectification module, and the rectification module carries out rectification to alternating current, and exports direct current for first LED String and the second LED string are powered, it is characterised in that the LED linear constant-current drive circuit also includes serioparallel exchange Module, the first constant-current driven module, the second constant-current driven module, the 3rd constant-current driven module and switch module;
The first end of the serioparallel exchange module, the input of the first LED string and second constant-current control module Input is connected to altogether the first output end of the rectification module, and the second end of the serioparallel exchange module, first constant current are driven The output end of dynamic model block, the output end of the 3rd constant-current control module and the second output end of the rectification module are connected to altogether Ground, the input of first constant-current control module is connected to altogether the switch module with the output end of the first LED string Input, the voltage input end and controlled end of first constant-current driven module respectively with the output end of the serioparallel exchange module With control end connection, the controlled end and output end of second constant-current driven module respectively with the output end of the switch module and The input connection of the second LED string, the output end of the second LED string is defeated with the 3rd constant-current control module Enter end connection;
When the output voltage of the rectification module is less than or equal to the first predetermined voltage threshold, the switch module shut-off, institute State the first LED string and the second LED connection in series-parallel connection, first constant-current control module and second current constant control Module carries out current constant control to the first LED string and the second LED string respectively;When the output electricity of the rectification module Pressure rises to more than the first predetermined voltage threshold and continues to rise and during less than the second predetermined voltage threshold, the serioparallel exchange mould Block is adjusted to the output current of first constant-current control module, and then the input power to late-class circuit carries out invariable power Control;When the output voltage of the rectification module is continued to rise to more than or equal to the second predetermined voltage threshold, the switch Module is turned on, and the first current constant control mould and second constant-current control module are turned off, the first LED string and described the Two LED strings are connected in series, and the 3rd constant-current control module is carried out to the first LED string and the second LED string Current constant control.
10. a kind of LED light device, is connected with AC power, and including the first LED string and the second LED string, its feature exists In the LED light device also includes the LED linear constant-current drive circuit as described in claim 1-9 any one.
CN201621279698.6U 2016-11-24 2016-11-24 Linear constant -current drive circuit of LED and LED lighting device Active CN206164934U (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106793253A (en) * 2016-11-24 2017-05-31 深圳市明微电子股份有限公司 A kind of LED linear constant-current drive circuit and LED light device
CN110505730A (en) * 2018-05-18 2019-11-26 华润矽威科技(上海)有限公司 Linear LED drive circuit and the linear LED driving method of full voltage input

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106793253A (en) * 2016-11-24 2017-05-31 深圳市明微电子股份有限公司 A kind of LED linear constant-current drive circuit and LED light device
CN106793253B (en) * 2016-11-24 2018-12-28 深圳市明微电子股份有限公司 A kind of LED linear constant-current drive circuit and LED light device
CN110505730A (en) * 2018-05-18 2019-11-26 华润矽威科技(上海)有限公司 Linear LED drive circuit and the linear LED driving method of full voltage input

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